Scientists from Russia, the US and China have predicted the existence of phagraphene, which they describe as a 'patchwork' analogue of graphene.
"Unlike graphene, a hexagonal honeycomb structure with atoms of carbon at its junctions," said team leader Artyom Oganov from the Moscow Institute of Physics and Technology, "phagraphene consists of penta, hexa and heptagonal carbon rings."
In graphene, each carbon atom has three electrons bound to electrons in neighbouring atoms. The fourth electron of each atom is 'delocalised', which allows graphene to conduct electricity. However, delocalised electrons in graphene behave strangely: they all have the same velocity, possess no inertia and appear to have no mass – properties dictated by so called Dirac cones.
Phagraphene – expected to have the same properties as graphene – also features Dirac cones and electrons behave similarly. "In phagraphene, due to the different number of atoms in the rings, the Dirac cones are 'inclined'," said Oganov. "That is why the velocity of electrons in it depends on the direction. It would be very interesting to see where it might be useful to vary the electron velocity."
Author
Graham Pitcher
Source: www.newelectronics.co.uk